Comminution apparatus

ABSTRACT

Comminution apparatus including two components rotating in opposite directions at different speeds and having a plurality of radially extending, elongated elements for reducing in size material fed into the nip between the components.

United States Patent [191 Risko et al.

[ Jan. 22, 1974 1 COMMINUTION APPARATUS [75] Inventors: Donald G. Risko; Donald R. Bosten;

Michael Rusnak, all of Pittsburgh, Pa.

[73] Assignee: Rockwell International Corporation,

Pittsburgh, Pa.

[22] Filed: Jan. 19, 1972 [21] Appl. No.: 219,012

[52] U.S. Cl 24l/101.7, 56/199, 241/222, 241/235 [51] Int. Cl. B02c 21/02, B02c 4/02 [58] Field of Search 241/227, 235, 242, 243, 241/101.7, 191, 195, 222; 56/202, 199

[56] References Cited UNITED STATES PATENTS 2,826,300 3/1958 Ross 241/227 X 3,197,949 8/1965 Waag.... 56/202 3,346,197 10/1967 Sagar 241/235 X 3,412,769 1l/1968 Howard 241/227 X 3,412,770 11/1968 .lohnson.... .l 241/243 3,496,706 2/ 1970 Mattson 56/202 X 3,622,083 11/1971 Greenewald 241/235 X Primary ExaminerGranvil1e Y. Custer, Jr. Assistant Examinerl-loward N. Goldberg 5 7] ABSTRACT Comminution apparatus including two components rotating in opposite directions at different speeds and having a plurality of radially extending, elongated elements for reducing in size material fed into the nip between the components.

15 Claims, 3 Drawing Figures PATENTEI] JAN 22 I974 SHEHIBFZ COMMINUTION APPARATUS This invention relates to novel, improved comminution apparatus.

The principles of the present invention are particularly adaptable to the. construction of leaf shredding machines, and they will be developed with reference to this type of machine. However, it is to be understood that this is simply for expediency and is not intended to limit the scope of protection to which we consider ourselves entitled.

The disposal of leaves presents a significant problem because of their bulk. As a result, a variety of leaf shredders have been developed and made commercially available. These machines, which are gasoline engine powered, include rotating knives into which the leaves are fed from a hopper. The rotating knives disintegrate the leaves which are discharged into a bag. The shredded leaves of course occupy much less space than in their original form, considerably facilitating the task of disposing of them.

These heretofore available leaf shredders have a number of disadvantages. They are comparatively heavy and difficult to move from place-to-place and are expensive.

They are also easily damaged. invariably rocks, bones, and similar objects are removed with the leaves and fed into the shredder where they can do considerable damage to the rotating knives. The knives can also convert the foreign objects into potentially dangerous missiles.

Furthermore, the shredding capabilities of these heretofore available machines is low, making the processing of any significant quantity of leaves an extended and tedious process.

We have now invented novel, improved comminution apparatus for shredding leaves and comparable uses which do not suffer from the disadvantages enumerated above. Briefly, the novel machines of the present invention employ for comminution a pair of contrarotating components which revolve at different speeds. Each of these components has a large number of elongated, semiflexible elements extending radially from a central shaft. The two components are so located that the free ends of the radial elements are contiguous as the components rotate. The leafy or other material to be shredded is fed into the nip between the two rotating components. As the leaves pass through the nip they are disintegrated and discharged through an outlet in the housing of the machine where they can be bagged or otherwise collected.

Wire brushes can be employed as the comminuting components of our novel machines, and the wire brushes can be driven at the requisite different speeds and in opposite directions by a low horsepower electrical motor and an extremely simple drive train. Aside from those components just mentioned and a few additional components such as wheels to make them transportable, our novel machines are fabricated of sheet metal. Thus, our machines employ only a relatively small number of inexpensive components which are easily assembled. They can accordingly be economically manufactured.

Because of their construction, our novel machines are also relatively light and compact and therefore easily moved from one place to another. In addition, our novel machines have proven to be surprisingly efficient and to be capable of reducing the leaves or other material fed to them at an unexpectedly high rate, making them usable even where large quantities of materials are involved.

Furthermore, our novel machines are not susceptible to damage from foreign objects. As such objects pass through the nip between the contrarotating components, the radial elements of the latter simply flex aside and allow the foreign object to pass through. This of course also eliminates the possibility of the foreign objects being flung back out of the feed hopper and injuring the operator or causing other damage.

From the foregoing it will be apparent that the primary object of our invention is the provision of novel, improved comminution apparatus.

Another primary but somewhat more specific object of the present invention resides in the provision of comminution apparatus which is particularly useful for shredding leaves and comparable material.

Other important but still more specific objects of the invention reside in the provision of comminution apparatus useful for the purposes just described:

I. which is simple, inexpensive, and'easy to manufacture.

2. which is relatively light and compact and therefore easily moved from location-to-location.

3. which is efficient and has a high capacity and is therefore well-suited for applications where comminution of a large volume of material is involved.

4. which is not easily damaged by the ingestion of hard foreign objects.

5. which is safe to use.

6. which has various combinations of the foregoing attributes.

Other objects and advantages along with other important features of the present invention will become apparent from the appended claims and as the ensuing detailed description and discussion proceeds in conjunction with the accompanying drawing, in which:

FIG. 1 is a side view of comminution apparatus which embodies and is constructed in accord with the principles of the present invention and which is designed particularly for shredding leaves;

FIG. 2 is a horizontal section through the apparatus of FIG. 1, showing its internal operating components; and

FIG. 3 is a fragmentary view of the apparatus of FIG. 1, looking in the direction of arrows 3-3 of FIG. 2.

Referring now to the drawing, FIG. 1 illustrates a shredder 20 in accord with the principles of the present invention, which is particularly designed for shredding leaves and like material to reduce its bulk. Shredder 20 includes a hopper 22 from which the material to be shredded flows into a shredding unit 24 consisting of a casing 26 housing two contrarotatable shredding components 28 and 30. The material to be shredded passes through the nip 32 between the shredder components 28 and 30 and is discharged from the shredder unit through an outlet opening 34 in shredder unit casing 26. Typically, the shredded material will be collected in a bag or the like (not shown). A bag support 36 is provided to hold the open end of the bag in the proper relationship to outlet opening 34 so that the shredded material will be discharged into the bag.

The shredder components 28 and 30 are rotated by a motor 38 housed in a motor housing 40 and controlled by an on-off switch 42 and, also, by a drive train 44 surrounded by a protective drive train housing or cover 46.

For leaf shredding and similar applications, it is desirable that shredder 20 be easily movable from place-toplace. It is accordingly provided with wheels 48 and a handle 50.

The contrarotating shredding components of shredder 20 are preferably wire brushes having a right cylindrical configuration. The two brushes have central shafts 51 and 52 to which flexible, radially extending,

wire bristles 54 are fixed in any convenient fashion. The two wire brushes are supported in housing 26 with the free ends of the two sets of bristles 54 in contiguous relationship at nip 32 for rotation about parallel spaced apart, horizontal axes by bearings 56 bolted to the front and rear, vertically extending walls 58 and 60 of housing 26.

The motor 38 by which brushes 28 and 30 are rotated is supported in any convenient fashion in housing 40, which has a horizontal, rectangular configuration and is provided with heat dissipating louvers 62 and fixed in any convenient manner to the front wall 58 of casing 26. The output shaft 64 of the motor is axially aligned with and connected to the shaft 52 of brush 30 for rotation therewith by a pin 66. The pin extends through the motor output shaft and a U-shaped fitting 68 fixed to one end of shaft 52.

For shredder 20 to operate efficiently, brushes 28 and 30 must rotate in opposite directions with the two sets of bristles 54 moving downwardly at nip 32. Also, for best results, the two brushes should rotate at different speeds. We employ drive train 44 to rotate brush 28 in the opposite direction and at a different speed from brush 30.

The input element of the drive train is a pinion 70 formed on the end of shaft 52 opposite fitting 68. Pinion 70 meshes with a gear 72 fixed to an intermediate shaft 74, which is rotatably supported from the rear wall 60 of casing 26 in a bearing 76. Consequently, the intermediate shaft rotates in the opposite direction from and at a slower speed than pinion 70 and the brush shaft 52 on which the pinion is formed. This oppositely directed, slower rotation of shaft 74 is transmitted to the shaft 51 of brush 38 by sprockets 78 and 80 respectively fixed to intermediate shaft 74 and to brush shaft 57 adjacent spacer 81 and by a sprocket chain 82. The drive chain is trained over and drivingly engaged with sprockets 78 and 80 as shown in FIG. 2.

In addition to the components just discussed, the drive train also preferably includes a support for the outboard end of intermediate shaft 74. In the exemplary embodiment of the invention shown in FIG. 2, this support is a bar 84. At one end, bar 84 is supported by brush shaft 51, which extends through it. Intermediate its ends, bar 84 is fixed as by a screw 86 to a bracket 88 which, in turn, is bolted or otherwise fixed to the rear wall 60 of housing 26. A bearing 90 is fitted in an aperture 92 in the end of bar 84 opposite shaft 52. The outboard end of shaft 74 extends through this bearing, supporting it from bar 84.

As indicated above, the drive train 44 is preferably surrounded by a protective housing 46. This is a safety measure and, also, keeps foreign material from the drive train components. Housing 46, which has a rectangular configuration and may be made of sheet metal, can be fastened in any desired manner to the rear wall 60 of housing 26 although it is preferred that housing 46 be detachable to provide access to the drive train for servicing.

Referring now to both FIGS. 1 and 2, the hopper 22 from which the material to be comminuted flows into the shredding unit has a frusto-pyrimidal configuration and, again, may be of sheet metal construction. The hopper has an open top 94 and an open bottom 96 and is attached as by welding to the top wall 98 of housing 26. The hopper and housing top wall are removably attached to housing 26 by retainers 99 which extend through top wall 98 and are threaded into fittings (not shown) fixed to the side walls of housing 26. Top wall 98 and hopper 22 can consequently be quickly removed to provide access to the inside of housing 26 and brushes 28 and 30 through an opening 101 formed in the top wall 98 of housing 26 in registry with the open lower end of hopper 22.

As shown in FIG. 2, this opening is directly above the contiguous portions of the contrarotating brushes 28 and 30. Accordingly, the material to be shredded falls from hopper 22 through opening 101 into the nip 32 between the two rollers and is disintegrated.

As shown in FIG. 1, the discharge opening 34 for the comminuted material is formed in the lower portion of and spans one of the two side walls 102 of casing 26. The discharge opening accordingly faces the lower portion of brush 30. As this brush rotates, its lower portion moves toward opening 34, propelling the comminuted material from casing 26 through the discharge opening.

As indicated above, this material will typically be collected in a bag or the like supported with its open end opposite the discharge opening by bag support 36. The bag support will typically consist of two rings 104 and 106 maintained in spaced apart relationship by spacers 108. The bag support is fixed in any convenient manner to the horizontally extending leg 110 of an L-shaped member 112. The member is removably supported from housing 26 by a bracket 114 through which the vertical leg 116 of member 112 extends. A pin 118 through support leg 116 and engaging the upper edge of bracket 114 vertically positions support member 1 12.

Referring now to FIGS. 1 and 3, whe wheels 48 by which shredder 20 is made transportable are supported from the bottom 120 of housing 26 by an elongated, typically tubular member 122, which also provides a third, ground-engaging support for the shredder. More specifically, the tubular member has two legs 124 joined by an integral, transversely extending, groundengaging leg 126. The legs 124 at inclined upwardly from leg 126 and are fixed in any convenient fashion to the bottom 120 of housing 26 at opposite sides thereof. At approximately the midpoints of housing side walls 102, legs 124 have depending portions 128 which terminate in outwardly directed, horizontal axles 130. As best shown in FIG. 3, wheels 48 are journalled on axles 130. They are laterally positioned as by protrusions 132 formed in the axles and are kept in place by frictional retainers 134.

The final major component of shredder 20, handle 50, may also be formed of tubular stock. At its lower end, the handle is fixed as by bolts 135 to the rear wall 136 of drive train cover 46. The handle extends upwardly and rearwardly from cover 46 and may be provided, at its upper end, with an appropriate grip 138.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. Comminution apparatus for shredding leaves and the like which comprises a housing having a chamber therein; a pair of shredder components in and extending the length of said chamber, said shredder components each including a plurality of thin, elongated, flexible radial elements; means mounting said shredder components in said chamber for rotation about parallel, horizontal axes with the free ends of the radially extending elements of the two shredder components in contiguous relationship to each other; means for introducing material to be shredded through said housing into the upper end of said chamber and into the nip between the shredder components; a discharge opening for comminuted material, said discharge opening being formed in said housing opposite the lower portion of one of said shredder components and being substantially equal in length to said one shredder component; and means for rotating the two shredder components toward each other with the lower portion of said one shredder component moving toward the discharge opening, whereby the material introduced into said chamber will be comminuted by the radially extending elements of the shredder components as it passes through the nip therebetween and will then be propelled from said chamber through the discharge opening by said one shredder component.

2. The comminution apparatus of claim 1, wherein the means for rotating said shredder components comprises a motor having an output shaft drive-connected to said one of said shredder components and drive train means connected between the two shredder components for rotating the other of the shredder components in the opposite direction from and at a lower speed than said one shredder component.

3. The comminution apparatus of claim 2, wherein each said shredder component comprises a rotatably mounted central shaft, said motor being driveconnected to one end of the shaft of said one of said shredder components; and wherein said drive train means comprises a pinion on the end of the shaft of said one shredder component opposite that end to which the motor is drive-connected, a rotatably mounted intermediate shaft, a gear rotatable with said intermediate shaft and meshed with said pinion for rotation thereby, and means drive-connecting said intermediate shaft to the central shaft of the other of said shredder components.

4. The comminution apparatus of claim 3, together with a motor housing fixed to and extending horizontally from the first-mentioned housing of the apparatus, said motor being mounted in the motor housing with its output shaft axially aligned with the shaft of said one of said shredder components.

5. The apparatus of claim 4, together with a protective housing surrounding the drive train means, said protective housing being fixed to the first-mentioned housing on the opposite side thereof from the motor housing.

6. The comminution apparatus of claim 3, wherein the means drive-connecting the intermediate shaft to the shaft of said other of said shredder components comprises sprockets fixed to said intermediate and shredder component shafts for rotation therewith and an endles s chain trained around the drivingly engaged with said sprockets.

7. The comminution apparatus of claim 1, together with wheel means supported from said housing to thereby make said comminution apparatus transportable from place-to-place.

8. The comminution apparatus of claim 7, together with handle means for moving the apparatus from place-to-place.

9. The comminution apparatus of claim 1, wherein each of said shredder components comprises a cylindrically configured wire brush.

10. The comminution apparatus of claim 1, wherein said housing has a vertically extending wall facing one of said shredder components, there being an outlet for the comminuted material formed in the lower portion of said wall.

1 l. The comminution apparatus of claim 10, together with means fixed to said housing for supporting a bag or the like in which the comminuted material discharged from the housing through the outlet therein can be collected.

12. The comminution apparatus of claim 1, wherein the shredder components are mounted for rotation about spaced horizontal, parallel axes.

13. The comminution apparatus of claim 1, wherein said shredder components are mounted for rotation about horizontal axes; wherein said housing has a top wall; and wherein there is an opening in said top wall above the contiguous portions of said shredder components, said apparatus further including a hopper fixed to said housing and extending upwardly therefrom, said hopper having an open upper end and an opening in the lower end thereof in registry with the opening in the top wall of said housing.

14. The apparatus of claim 13, together with means detachably fixing in place the top wall of said housing whereby it can be readily removed to afford access to the interior of the housing.

15. The apparatus of claim 1, wherein the means for rotating the shredder components includes a motor, said apparatus further including a motor housing extending horizontally from the first-mentioned housing and surrounding said motor; wheels for making the comminution apparatus transportable from place-toplace; and an elongated member fixed to said firstmentioned housing and having depending wheel supporting portions at opposite sides thereof, said wheels being rotatably fixed to the depending portions of said elongated member and said member further having a portion disposed below and extending transversely of the motor housing which is engageable with the surface on which the comminution apparatus is rested to, together with said wheels, support said comminution apparatus from said surface.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION- Patent No. 3,786,998 Dated January 22, 1974 Inventor(s) Donald C. Risko, Donald R. Bosten, Michael Rusnak It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 3, Line 44. delete "38" and substitute --28-.

Column 4, line 50,, delete "ar" and substitute "and-- Column 6, Line 9, delete "the" and substitute ---and--.

' Signed and sealed this 24th day of December 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. 7 c. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. Comminution apparatus for shredding leaves and the like which comprises a housing having a chamber therein; a pair of shredder components in and extending the length of said chamber, said shredder components each including a plurality of thin, elongated, flexible radial elements; means mounting said shredder components in said chamber for rotation about parallel, horizontal axes with the free ends of the radially extending elements of the two shredder components in contiguous relationship to each other; means for introducing material to be shredded through said housing into the upper end of said chamber and into the nip between the shredder components; a discharge opening for comminuted material, said discharge opening being formed in said housing opposite the lower portion of one of said shredder components and being substantially equal in length to said one shredder component; and means for rotating the two shredder components toward each other with the lower portion of said one shredder component moving toward the discharge opening, whereby the material introduced into said chamber will be comminuted by the radially extending elements of the shredder components as it passes through the nip therebetween and will then be propelled from said chamber through the discharge opening by said one shredder component.
 2. The comminution apparatus of claim 1, wherein the means for rotating said shredder components comprises a motor having an output shaft drive-connected to said one of said shredder components and drive train means connected between the two shredder components for rotating the other of the shredder components in the opposite direction from and at a lower speed than said one shredder component.
 3. The comminution apparatus of claim 2, wherein each said shredder component comprises a rotatably mounted central shaft, said motor being drive-connected to one end of the shaft of said one of said shredder components; and wherein said drive train means comprises a pinion on the end of the shaft of said one shredder component opposite that end to which the motor is drive-connected, a rotatably mounted intermediate shaft, a gear rotatable with said intermediate shaft and meshed with said pinion for rotation thereby, and means drive-connecting said intermediate shaft to the central shaft of the other of said shredder components.
 4. The comminution apparatus of claim 3, together with a motor housing fixed to and extending horizontally from the first-mentioned housing of the apparatus, said motor being mounted in the motor housing with its output shaft axially aligned with the shaft of said one of said shredder components.
 5. The apparatus of claim 4, together with a protective housing surrounding the drive train means, said protective housing being fixed to the first-mentioned housing on the opposite side thereof from the motor housing.
 6. The comminution apparatus of claim 3, wherein the means drive-connecting the intermediate shaft to the shaft of said other of said shredder components comprises sprockets fixed to said intermediate and shredder component shafts for rotation therewith and an endles s chain trained around the drivingly engaged with said sprockets.
 7. The comminution apparatus of claim 1, together with wheel means supported from said housing to thereby make said comminution apparatus transportable from place-to-place.
 8. The comminution apparatus of claim 7, together with handle means for moving the apparatus from place-to-place.
 9. The comminution apparatus of claim 1, wherein each of said shredder components comprises a cylindrically configured wire brush.
 10. The comminution apparatus of claim 1, wherein said housing has a vertically extending wall facing one of said shredder components, there being an outlet for the comminuted material formed in the lower portion of said wall.
 11. The comminution apparatus of claim 10, together with means fixed to said housing for supporting a bag or the like in which the comminuted material discharged from the housing through the outlet therein can be collected.
 12. The comminution apparatus of claim 1, wherein the shredder components are mounted for rotation about spaced horizontal, parallel axes.
 13. The comminution apparatus of claim 1, wherein said shredder components are mounted for rotation about horizontal axes; wherein said housing has a top wall; and wherein there is an opening in said top wall above the contiguous portions of said shredder components, said apparatus further including a hopper fixed to said housing and extending upwardly therefrom, said hopper having an open upper end and an opening in the lower end thereof in registry with the opening in the top wall of said housing.
 14. The apparatus of claim 13, together with means detachably fixing in place the top wall of said housing whereby it can be readily removed to afford access to the interior of the housing.
 15. The apparatus of claim 1, wherein the means for rotating the shredder components includes a motor, said apparatus further including a motor housing extending horizontally from the first-mentioned housing and surrounding said motor; wheels for making the comminUtion apparatus transportable from place-to-place; and an elongated member fixed to said first-mentioned housing and having depending wheel supporting portions at opposite sides thereof, said wheels being rotatably fixed to the depending portions of said elongated member and said member further having a portion disposed below and extending transversely of the motor housing which is engageable with the surface on which the comminution apparatus is rested to, together with said wheels, support said comminution apparatus from said surface. 